What is the general solution for cos(3x)=-(sqrt(2))/2 ?

The general solution for cos(3x)=-(sqrt(2))/2 is x= pi/4+(2pin)/3 ,x=(5pi}{12}+\frac{2pin)/3

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

cos(3x)=-(sqrt(2))/2

Solution

cos (3 x) = - \frac{2}{2}

Solution

x = \frac{π}{4} + \frac{2 πn}{3}, x = \frac{5 π}{12} + \frac{2 πn}{3}

Degrees

x = 4 5^{\circ} + 12 0^{\circ} n, x = 7 5^{\circ} + 12 0^{\circ} n

Solution steps

cos (3 x) = - \frac{2}{2}

General solutions for

cos (3 x) = - \frac{2}{2}

cos (x)

periodicity table with

2 πn

cycle:

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} cos (x) 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} cos (x) - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2} 0 \frac{1}{2} \frac{2}{2} \frac{3}{2}

3 x = \frac{3 π}{4} + 2 πn, 3 x = \frac{5 π}{4} + 2 πn

3 x = \frac{3 π}{4} + 2 πn, 3 x = \frac{5 π}{4} + 2 πn

Solve

3 x = \frac{3 π}{4} + 2 πn : x = \frac{π}{4} + \frac{2 πn}{3}

3 x = \frac{3 π}{4} + 2 πn

Divide both sides by

3

3 x = \frac{3 π}{4} + 2 πn

Divide both sides by

3

\frac{3 x}{3} = \frac{\frac{3 π}{4}}{3} + \frac{2 πn}{3}

Simplify

\frac{3 x}{3} = \frac{\frac{3 π}{4}}{3} + \frac{2 πn}{3}

Simplify

\frac{3 x}{3} : x

\frac{3 x}{3}

Divide the numbers:

\frac{3}{3} = 1

= x

Simplify

\frac{\frac{3 π}{4}}{3} + \frac{2 πn}{3} : \frac{π}{4} + \frac{2 πn}{3}

\frac{\frac{3 π}{4}}{3} + \frac{2 πn}{3}

\frac{\frac{3 π}{4}}{3} = \frac{π}{4}

\frac{\frac{3 π}{4}}{3}

Apply the fraction rule:

\frac{\frac{b}{c}}{a} = \frac{b}{c \cdot a}

= \frac{3 π}{4 \cdot 3}

Multiply the numbers:

4 \cdot 3 = 12

= \frac{3 π}{12}

Cancel the common factor:

3

= \frac{π}{4}

= \frac{π}{4} + \frac{2 πn}{3}

x = \frac{π}{4} + \frac{2 πn}{3}

x = \frac{π}{4} + \frac{2 πn}{3}

x = \frac{π}{4} + \frac{2 πn}{3}

Solve

3 x = \frac{5 π}{4} + 2 πn : x = \frac{5 π}{12} + \frac{2 πn}{3}

3 x = \frac{5 π}{4} + 2 πn

Divide both sides by

3

3 x = \frac{5 π}{4} + 2 πn

Divide both sides by

3

\frac{3 x}{3} = \frac{\frac{5 π}{4}}{3} + \frac{2 πn}{3}

Simplify

\frac{3 x}{3} = \frac{\frac{5 π}{4}}{3} + \frac{2 πn}{3}

Simplify

\frac{3 x}{3} : x

\frac{3 x}{3}

Divide the numbers:

\frac{3}{3} = 1

= x

Simplify

\frac{\frac{5 π}{4}}{3} + \frac{2 πn}{3} : \frac{5 π}{12} + \frac{2 πn}{3}

\frac{\frac{5 π}{4}}{3} + \frac{2 πn}{3}

\frac{\frac{5 π}{4}}{3} = \frac{5 π}{12}

\frac{\frac{5 π}{4}}{3}

Apply the fraction rule:

\frac{\frac{b}{c}}{a} = \frac{b}{c \cdot a}

= \frac{5 π}{4 \cdot 3}

Multiply the numbers:

4 \cdot 3 = 12

= \frac{5 π}{12}

= \frac{5 π}{12} + \frac{2 πn}{3}

x = \frac{5 π}{12} + \frac{2 πn}{3}

x = \frac{5 π}{12} + \frac{2 πn}{3}

x = \frac{5 π}{12} + \frac{2 πn}{3}

x = \frac{π}{4} + \frac{2 πn}{3}, x = \frac{5 π}{12} + \frac{2 πn}{3}

Popular Examples

2cos(x)+1=2

2 cos (x) + 1 = 2

sin(θ)= 5/9

sin (θ) = \frac{5}{9}

1+sin(x)=2sin^2(x)

1 + sin (x) = 2 sin^{2} (x)

sec(x)=2csc(x)

sec (x) = 2 csc (x)

cos^2(x)=0.75

cos^{2} (x) = 0.75

Frequently Asked Questions (FAQ)

What is the general solution for cos(3x)=-(sqrt(2))/2 ?
The general solution for cos(3x)=-(sqrt(2))/2 is x= pi/4+(2pin)/3 ,x=(5pi}{12}+\frac{2pin)/3